Transporting supplies has been an important concern in nearly every commercial, military, or other endeavor. A vast infrastructure has developed over the centuries to get supplies where they are needed as quickly and economically as possible, including ocean-borne shipping, railroads, airborne cargo, highways, and trucking. These developments handle the bulk of modern transportation requirements.
In some conditions, however, conventional transportation fails to deliver when and where the supplies are needed most. Catastrophes, both natural and man-made, often disrupt the usual supply chains for food, clean water, clothing, and medicine by damaging facilities, destroying railroad tracks, blocking roads, and wrecking bridges. Other supply conditions are likewise hostile to land- and sea-based supply chains. For example, supplying isolated troops or other personnel in remote areas may not be possible with trucks, railroads, and ships.
With the advent of large aircraft, aerial supply presented a practical method for supplying remote or cut-off areas. If the aircraft could land safely, the supplies could be unloaded manually and the aircraft could return to its base. If the aircraft could not land, however, supplies could be air-dropped, using a parachute to slow the descent of a container holding the supplies.
Air-dropped supplies, however, require the aircraft to approach the area where the supplies are needed, potentially exposing the crew to hostile fire or other high-risk conditions. Further, air-dropped supplies are subject to wind and weather conditions, making it difficult to place supplies where they are needed. Consequently, the supplies may not be accessible to those who need them, and may even be found and used by hostile personnel.